This application to continue as the Statistical and Data Management Center (SDMC) for the HIV Vaccine Trials Network (HVTN) is one of three applications comprising the Leadership Group of the HVTN. The HVTN scientific agenda focuses exclusively on RFA priority number 1: 'Vaccine Researchand Development." This application describes howthe Statistical Center for HIV/AIDS Research& Prevention (SCHARP) will achieve the aims of the RFAto (1) provide statistical leadership for the design, conduct, analysis and publication of Network clinical trials/studies; (2) provide central data management capability that includes randomization, data set and case report form design, central storage, security, processing and retrieval of study results; (3) provide data management and protocol training throughout the Network; (4) provide data-focused clinical trials implementation, and operation; and (5) contribute to cross-Network efforts in developing common data elements and data interfaces. SCHARP has extensive experience in the design, conduct and analysis of global HIV vaccine and prevention studies. Thus, the systems we propose to use for data collection, managment, monitoring, and analysis are all well tested and in accordance with ICH guidelines. SCHARP statisticians will also develop and deploy novel statistical methodologies to increase the efficiency and rigor of the proposed program of HlV vaccine trials. The HIV/AIDS epidemic continues to expand in almost all regions of the world, with approximately 4.8 million new infections in 2003 (UNAIDS 2004 Report on the Global AIDS Epidemic). Finding a safe, effective vaccine that will protect persons against infection and/or disease progression is an international public- health priority. Only through clinical trials held to the highest scientific and regulatory standards willthis goal be achieved.